correig2sig.m

阵列信号处理的工具箱

function sigOut = correig2sig(corrMats)

%CORREIG2SIG Calculates the square root of the eigenvalues of correlation matrices and converts the result to a radar signal.
%
%--------
%Synopsis:
%  sigOut = correig2sig(corrMats)
%
%Description:
%  Calculates the square root of the eigenvalues of several correlation
%  matrices and converts the result to a radar signal (RxRadarSigT).
%  This is actually not possible and allowed. The result is not a real radar 
%  signal.
%  The purpose with this function is to make it possible to plot correlation 
%  matrix eigenvalues with the plotting functions for radar signals, e.g.
%  the function "sigplot2".
%
%  NOTE: A "radar" signal created with this function can only be used for 
%  plotting, not for further processing.
%
%  NOTE: Now this functions returns the square root of the eigenvalues
%  instead of the eigenvalues. The reason for this is that a "radar signal" 
%  (RxRadarSigT) always should be an amplitude measure.
%
%Output and Input:
%  sigOut (RxRadarSigT ): The output radar signal which contains the
%    eigenvalue spectra.
%  corrMats (RxCorrMatT): One or several spatial correlation matrices.
%
%--------
%Notations:
%  Data type names are shown in parentheses and they start with a capital
%  letter and end with a capital T. Data type definitions can be found in [1]
%  or by "help dbtdata".
%  [D] = This parameter can be omitted and then a default value is used.
%  When the [D]-input parameter is not the last used in the call, it must be
%  given the value [], i.e. an empty matrix.
%  ... = There can be more parameters. They are explained under respective
%  metod or choice.
%
%Examples:
%
%
%
%Software Quality:
%  (About what is done to ascertain software quality. What tests are done.
%   Known bugs.)
%
%Known Bugs:
%
%References:
%  [1]: Bj鰎klund S.: "DBT, A MATLAB Toolbox for Radar Signal Processing.
%    Reference Guide", FOA-D--9x-00xxx-408--SE, To be published.
%
%See Also:
%  ecorrm, sigplot2

%   *  DBT, A Matlab Toolbox for Radar Signal Processing  *
% (c) FOA 1994-2000. See the file dbtright.m for copyright notice.
%
%  Start        : 990501 Svante Bj鰎klund (svabj).
%  Latest change: $Date: 2000/10/16 15:20:15 $ $Author: svabj $.
%  $Revision: 1.7 $
% *****************************************************************************

% ****************** Error check input parameters ******************

chkdtype(corrMats,'RxCorrMatT')


% ****************** Spectrum size ******************

sizeSpec = sizem(corrMats.corrMat);
noChannels = sizeSpec(1);
noPulses = 1;	
  % Can only store correlation matrix for a single pulse in RxCorrMatT data 
  % type.
noRanges = sizeSpec(3);
noExtras = sizeSpec(4);
noCPIs   = sizeSpec(5);
noTrials = 1;
  % Can only store correlation matrix for a single trial in RxCorrMatT data 
  % type.

% ****************** Create output variable ******************

antenna = defant;
waveform = defwave(1,1,1,1,1);
sigOut = RxRadarSigT(zeros([noPulses, noRanges,  noChannels,  noExtras, ...
  noCPIs, noTrials]),{antenna, waveform});

% ****************** Loops ******************

for trialLoop = 1:noTrials
  for cpiLoop = 1:noCPIs
    for extraLoop = 1:noExtras
      for rangeLoop = 1:noRanges
        for pulseLoop = 1:noPulses
          %eigVals = (flipud(sort(abs(eig(corrMats.corrMat(:,:,rangeLoop, ...
          %  extraLoop, cpiLoop))))));
          %  % Calculate and sort the eigenvalues.

          eigVals = svd(corrMats.corrMat(:,:,rangeLoop, extraLoop, cpiLoop));
            % Calculate eigenvalues of the spatial correlation matrix.
          eigVals = eigVals(:);
          sigOut.signals(pulseLoop,rangeLoop,:,extraLoop,cpiLoop,...
            trialLoop) = sqrt(eigVals);
        end%for pulseLoop
      end%for rangeLoop
    end%for extraLoop
    infoStr = sprintf('correig2sig: cpiLoop = %d(%d), range = %d(%d)\r',cpiLoop, noCPIs, rangeLoop, noRanges);
    dbtinfo(infoStr,1);
  end%for cpiLoop
  dbtinfo('');	%New line.
end%for trialLoop